Native fluorescence of oral cavity structures: An experimental study in dogs

Abstract

Objective: The aim of this study was to compare the fluorescence of different areas of the buccal mucosa of dogs. Background Data: Native fluorescence occurs in many animal and plant tissues following excitation by ultraviolet (UV) light. The fluorescence spectrum characteristic of a given tissue may vary with changes in tissue composition and organization. Hence, this optical phenomenon provides a reliable and minimally invasive diagnostic tool for examining tissues in normal and pathological conditions. The oral cavity contains a variety of structures, including the lips, tongue, palate, and gingiva that differ in their location and function. These structures can be easily traumatized or display different degrees of keratinization. Methods: The study sample was 20 healthy, adult, mongrel dogs of both sexes. The dogs were anesthetized and manipulated in compliance with institutional guidelines. The fluorescence spectra were obtained using a "plug-in" spectrometer and optical fibers, with a final resolution better than 2 nm. The fluorescence of seven different areas (floor of the mouth, palate, gingiva, dorsal and ventral surface of tongue, buccal mucosa, and teeth) was examined. A UV-Hg lamp (emission wavelength, 350-410 nm) was used for excitation. Results: One hundred and forty spectra were collected from various regions of the oral cavity, and all of them showed similar profiles, with maximum fluorescence of 500-520 nm. Conclusion: The similarity of the spectra for the different sites allowed us to establish a standard fluorescence spectrum of the buccal cavity.